It's the time of year when damselflies are everywhere, even in my garden with no pond. The one above is a male Red-eyed damselfly that was just one amongst clouds of the things around a lake I recently visited in Norfolk. I had to study my picture closely to check that it wasn't a Small red-eyed damselfly, but I think that the shape and colour pattern of the tail is the giveaway, not to mention I don't remember it being tiny.

I spotted this quite large freshwater mussel in the shallow waters at the edge of a lake in Norfolk. Beneath the gunk it looks like it's probably quite a rich mixture of yellow/green/brown and I suspect it's a member of the Unionidae family as they look very similar. I don't see them very often, though apparently they're very common, especially in canals, though I remember finding a very large shell (perhaps 15cm) at the edge of a lake as a boy.

Update: thanks to Matt/Matthew who comments that it could be a Painter's Mussel (Unio pictorum) and I think he's absolutely right. Apparently the Painter's Mussel is so called because it made a perfect receptable for artists' paint!

At my favourite watery wildlife spot I saw a new critter yesterday, though I knew what they were the minute I saw them: whirligig beetles. There are some great close-up photos and facts on that linked page – well worth a look. My photo above shows how metallic they appear on the surface – seedlike blobs of mercury almost.

I recognised them instantly because they were clearly beetles, and were whizzing around in circles and figures on eight on the surface in a fairly hectic manner. Particularly notable is that they have eyes split into two, for seeing above and below the water (the link above has a particularly good picture of this).

Norfolk Wildlife Trust have a great website with resources to help in surveying many different kinds of wildlife, from ponds to fungi. The forms are designed to be sent back to report on wildlife in Norfolk, but there's so much great information and guidance that they should be of interest to anybody.

More from UKNB's 2010 tour of Northumberland. Today a small collection of photos demonstrating the wonderful autumnal colours that have been on display. It seems to have been a good year for it, and a few days with wonderful warm but weak sunshine have lit the trees up just so.

These are all from the Cragside Estate, which is a wonderful place to walk around at any time of year.

Another interesting bird photo from Clumber Park. It might not be immediately be obvious, but this Mute swan is having a shake down to throw water from its feathers. You can just see drops of water being flung out if you look very closely. A video might have done it more justice, but that long neck shimmied in a rapidly undulating S shape that was quite a sight.

The BBC reports on an invasive species of shrimp found in the Grafham Water reservoir in Cambridgeshire. Originally from the region between the Black and Caspian seas, it's thought to have spread to Western Europe via the Danube. Apparently it's a vicious little beastie that kills all sorts of other water fauna and could threaten them: native shrimps, water boatmen, even fish.

Should we worry? As with so many similar stories, it does raise the difficult question of whether we should or shouldn't interfere in the natural comings and goings of species. It's no doubt gone on down the millennia before we were on the scene, with vast numbers of species dying out and new ones coming to prominence before maybe fading away themselves. We seem to be keen to stop time and freeze the natural world as it is – but that sounds fairly unnatural in itself.

The BBC reports that Red swamp crayfish have been found in London's Regents Canal. Like the Signal crayfish this is an American invader that threatens to oust the smaller native crayfish, though it's not such a big-clawed lobster as the Signal.

More fish from the River Lea at Stanborough Park, Welwyn. I'm not great at identifying fish (you seldom see them clearly anyway unless you're an angler) but I reckon these are Dace. Quite slim and sleek, with a large eye compared to the Barbel in my previous post from the same spot, though not quite as big. here's another shot with one of each (I think) Barbel above, Dace below – each perhaps 25cm long. Or maybe I've got three species here in total?

Update: having found a good book on dish with photos, they could easily be Chub instead of Dace.